Fine Structure and Optical Depth in the Solar Transition Region
Abstract
Unresolved fine structure in the solar transition region (TR) has long been inferred from measurements of density-sensitive line pairs showing low filling factor (< 0.01). Low filling factor models for the structure of the He II source region, however, have not been well studied. We propose a highly structured model of the lower atmosphere in which He II is formed at low filling factors, leading to high emission measure and an optically thin He II line. This transparent TR material is juxtaposed with absorbing chromospheric structures, leading to the nearly uniform center to limb behavior of the He II line as observed.
- Publication:
-
AAS/Solar Physics Division Abstracts #42
- Pub Date:
- May 2011
- Bibcode:
- 2011SPD....42.1739P